By means of transient linear acceleration of the whole body along the interaural axis, we examined the LVOR in six patients with hereditary cerebellar ataxia due to mutations of the calcium channel gene CACNA1A, five with spinocerebellar ataxia type 6 (SCA6) and one with episodic ataxia type 2 (EA-2).
Different CACNA1A mutations have been identified in other autosomal dominant conditions: mutations leading to a truncated protein in episodic ataxia type 2 (EA2), small expansions of a CAG trinucleotide in spinocerebellar ataxia type 6 and also in three families with EA2 features, and, finally, a missense mutation in a single family suffering from episodic ataxia and severe progressive PCA.
Expression levels of CACNA1A encoding α1A subunit were similar between SCA6 and control neurons, and no differences were found in the subcellular distribution of Ca<sub>V</sub>2.1 channel protein.
Familial hemiplegic migraine type 1, spinocerebellar ataxia type 6 (SCA6) and episodic ataxia type 2 (EA2) are allelic disorders associated with mutations in the CACNA1A gene, which encodes the alpha1 subunit of the P/Q-type calcium channel (Ca(V)2.1).
Familial hemiplegic migraine type 1, episodic ataxia type 2, and spinocerebellar ataxia type 6 are distinct neurological disorders associated with mutations in the CACNA1A gene.
Familial hemiplegic migraine, episodic ataxia type 2 (EA2), and spinocerebellar ataxia type 6 are allelic disorders of the CACNA1A gene (coding for the alpha(1A) subunit of P/Q calcium channels), usually associated with different types of mutations (missense, protein truncating, and expansion, respectively).
Here we show that a perceptual disturbance of verticality is indeed present in people with a genetically determined and pure form of cerebellar degeneration (spinocerebellar ataxia type 6; SCA 6), but is only revealed under dynamic visual conditions.
Here, we studied the cerebellar gene expression patterns of young Sca6-MPI(118Q/118Q) knockin (KI) mice, which expressed mutant Cav2.1 from an endogenous locus and recapitulated many phenotypic features of human SCA6.
In view of the known role of p62 in protein degradation as well as aggresome/sequestosome formation, the p62 aggregate formation observed in the present study suggests that SCA6not only is associated with an impairment of the calcium channel function and an elongated polyglutamine stretch in CACNA1A, but also with a defective protein handling by the protein quality control system.
Interestingly, distinct types of CACNA1A mutations have been identified in familial hemiplegic migraine (missense mutations) and spinocerebellar ataxia type 6 (SCA-6) progressive cerebellar ataxia (expanded CAG repeats).
Missense and splice site mutations have been found in FHM and episodic ataxia type 2, respectively, whereas a CAG repeat in the CACNA1A gene was found expanded in patients with SCA6.
Moreover, whereas healthy subjects (n = 31) were found to be able to discriminate subtle differences in the kinematics of observed limb movements of others, patients suffering from spinocerebellar ataxia type 6 (SCA6; n = 21) were severely impaired in performing such tasks.
Mutations in the 1A-subunit of the brain P/Q-type calcium channel gene CACNA1A are responsible for spinocerebellar ataxia type 6 (SCA6), familial haemiplegic migraine (FHM) and episodic ataxia type 2 (EA2).
Mutations in the CACNA1A gene that encodes the pore-forming alpha1 subunit of human voltage-gated CaV2.1 (P/Q-type) Ca2+ channels cause several autosomal-dominant neurologic disorders, including familial hemiplegic migraine type 1 (FHM1), episodic ataxia type 2, and spinocerebellar ataxia type 6 (SCA6).